Ok. I didn't anticipate this would be a drawn out process. I just Ford's
suggestion fixed the issue of changing values but recreated the problem of
accessing an individual's information like so: population[2] .
population[:,2] did not work either. I tried other changes to the syntax
but to no avail. It fails at the last line. Any ideas would be
appreciated.
type Person
infected::Bool
vaccinated::Bool
dead::Bool
history::Vector{Int}
end
type Population <: AbstractArray
individuals::Vector{Person}
end
Population() = Population(Person[])
Base.push!(p::Population, x::Person) = push!(p.individuals, x)
function Base.getindex(pop::Population, field::Symbol)
[getfield(x, field) for x in pop.individuals]
end
setindex!(p::Population, value, field::Symbol, index...) =
p.individuals[index...].(field) = value
getindex(p::Population, field::Symbol, index...) =
p.individuals[index...].(field)
Base.show(io::IO, p::Person) = print(io, "Person(infected=", p.infected, ",
vaccinated=", p.vaccinated, ", dead=", p.dead, ", history=", p.history)
population = Population()
push!(population, Person(true, false, true, [3,4,5]))
push!(population, Person(false, true, false, Int64[3,4,5]))
#Show that it works
population[:infected]
population[:infected,1]
population[2]
LoadError: MethodError: `size` has no method matching size(::Population)
Closest candidates are:
size(::Any, !Matched::Integer, !Matched::Integer, !Matched::Integer...)
while loading In[1], in expression starting on line 36
in getindex at abstractarray.jl:488
On Saturday, June 4, 2016 at 3:11:18 PM UTC-4, Ford O. wrote:
>
> I would like to discourage you from passing symbols as an array index but
> I guess you gonna do it anyway...
>
>
> So if you really want it, here it is:
> setindex!(p::Population, value, field::Symbol, index...) = p.individuals[
> index...].(field) = value
> getindex(p::Population, field::Symbol, index...) = p.individuals[index
> ...].(field)
>
> Usage
> population[:infected, 1]
> population[:infected, 1] = false
>
>
>
>
> On Saturday, June 4, 2016 at 2:19:02 PM UTC+2, Christopher Fisher wrote:
>>
>> I was wondering if someone would be willing to help me with creating
>> user-defined types. I've been using Julia for about two years now but I am
>> new to the idea of creating custom types. I'm trying to create a population
>> of agents/individuals in a simple epidemiological simulation. I would like
>> the population of individuals to be structured as a 2 dimensional array
>> with rows as individuals and columns as properties. This would be somewhat
>> similar to a DataFrame, but potentially more flexible. I want to be able to
>> index an individual like so: population[1]. This woud list all of the
>> information for individual 1. I would also like to be able to look at an
>> attribute across individuals: population.infected or population[:infected].
>> At the same time, I would like to have to flexibility of using an array to
>> keep track of individuals: typeof(population.history[1]) is Array{Int64,1}.
>> Based on existing documentation and examples, I have only been able to
>> create individuals but cannot figure out how to create a population as
>> described above:
>>
>> type Person
>> infected::Int64
>> vaccinated::Int64
>> dead::Int64
>> history::Array{Int64,1}
>> end
>>
>> Any help would be greatly appreciated.
>>
>
